“Medicare for all” was a fringe idea just a couple years ago, but it’s moved front and center in the political conversation ahead of the 2020 presidential election. Democratic candidates are getting asked about Medicare for all or announcing plans to implement it, and health care stocks are sliding at the suggestion of it. Now, we’re still a long way off from this kind of seismic change to the way Americans get their health care, but in the meantime, Vox senior editor Sarah Kliff is here to talk us through what Medicare for all is, exactly, and how it might change the economy.